/* Overbilled: one stylesheet, no web fonts (fast on mobile data). */
:root {
  --ink: #14213d;
  --text: #22262e;
  --muted: #5b6270;
  --bg: #fbfaf7;
  --panel: #ffffff;
  --line: #e3e1da;
  --accent: #0f6e5c;        /* deep green: buttons and links */
  --accent-ink: #ffffff;
  --warn-bg: #fff4e0;
  --warn-line: #e5b45a;
  --err-bg: #fdecea;
  --err-line: #d9786c;
  --ok-bg: #e9f5ef;
  --ok-line: #7cb79a;
  --radius: 10px;
  --max: 68rem;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ink: #e8ecf4; --text: #dfe2e8; --muted: #a3a9b6; --bg: #12151b; --panel: #1a1e26; --line: #2c313c;
    --accent: #4fc0a5; --accent-ink: #0b1512;
    --warn-bg: #2d2614; --warn-line: #8a6a26; --err-bg: #2e1a18; --err-line: #9a4b42; --ok-bg: #15281f; --ok-line: #3f7c5f;
  }
}
:root[data-theme="dark"] {
  --ink: #e8ecf4; --text: #dfe2e8; --muted: #a3a9b6; --bg: #12151b; --panel: #1a1e26; --line: #2c313c;
  --accent: #4fc0a5; --accent-ink: #0b1512;
  --warn-bg: #2d2614; --warn-line: #8a6a26; --err-bg: #2e1a18; --err-line: #9a4b42; --ok-bg: #15281f; --ok-line: #3f7c5f;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 17px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
/* Long addresses (the Regulator's complaints form, email addresses) wrap instead of widening the page on a phone. */
main, footer.site { overflow-wrap: break-word; }
a { color: var(--accent); }
img { max-width: 100%; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 16px; }

header.site { border-bottom: 1px solid var(--line); background: var(--panel); }
header.site .wrap { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 60px; flex-wrap: wrap; }
.brand { font-weight: 800; font-size: 1.25rem; color: var(--ink); text-decoration: none; letter-spacing: -0.01em; }
.brand span { color: var(--accent); }
nav.site a { color: var(--text); text-decoration: none; margin-left: 1rem; font-size: 0.95rem; }
nav.site a:hover { color: var(--accent); }

h1, h2, h3 { color: var(--ink); line-height: 1.2; letter-spacing: -0.01em; }
h1 { font-size: clamp(1.9rem, 5vw, 2.8rem); margin: 0 0 0.6rem; }
h2 { font-size: clamp(1.35rem, 3vw, 1.75rem); margin: 2.5rem 0 0.8rem; }
h3 { font-size: 1.1rem; margin: 1.4rem 0 0.4rem; }
p.lede { font-size: 1.15rem; color: var(--muted); max-width: 40rem; }

.hero { padding: 3rem 0 2rem; }
.cta { display: flex; gap: 0.8rem; flex-wrap: wrap; margin: 1.4rem 0 0.6rem; }
.btn {
  display: inline-block; padding: 0.8rem 1.2rem; border-radius: var(--radius); font-weight: 650;
  text-decoration: none; border: 2px solid var(--accent); cursor: pointer; font-size: 1rem;
}
.btn.primary { background: var(--accent); color: var(--accent-ink); }
.btn.secondary { background: transparent; color: var(--accent); }
.small { font-size: 0.9rem; color: var(--muted); }

.grid { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.1rem 1.2rem; }
.card h3 { margin-top: 0; }
.step-num { display: inline-block; width: 1.8rem; height: 1.8rem; border-radius: 50%; background: var(--accent); color: var(--accent-ink); text-align: center; line-height: 1.8rem; font-weight: 700; margin-right: 0.4rem; }

.price { font-size: 2.2rem; font-weight: 800; color: var(--ink); }
.note { background: var(--warn-bg); border: 1px solid var(--warn-line); border-radius: var(--radius); padding: 0.8rem 1rem; }

details { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 0.8rem 1rem; margin: 0.5rem 0; }
summary { font-weight: 650; cursor: pointer; color: var(--ink); }

footer.site { margin-top: 4rem; border-top: 1px solid var(--line); padding: 2rem 0; color: var(--muted); font-size: 0.9rem; }
footer.site a { color: var(--muted); }

/* Checker */
form.check fieldset { border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); padding: 1rem; margin: 0 0 1rem; }
form.check legend { font-weight: 700; color: var(--ink); padding: 0 0.3rem; }
fieldset.details { border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); padding: 1rem; margin: 0 0 1rem; }
fieldset.details legend { font-weight: 700; color: var(--ink); padding: 0 0.3rem; }
label { display: block; font-weight: 600; margin: 0.6rem 0 0.2rem; }
input, select {
  font: inherit; padding: 0.55rem 0.6rem; border: 1px solid var(--line); border-radius: 8px;
  background: var(--bg); color: var(--text); width: 100%; max-width: 20rem;
}
table.readings { border-collapse: collapse; width: 100%; }
table.readings th, table.readings td { text-align: left; padding: 0.3rem 0.3rem 0.3rem 0; }
table.readings input, table.readings select { max-width: 11rem; }
.tabs { display: flex; gap: 0.4rem; flex-wrap: wrap; margin: 1rem 0; }
.tabs button { font: inherit; padding: 0.5rem 0.9rem; border-radius: 999px; border: 1px solid var(--line); background: var(--panel); color: var(--text); cursor: pointer; }
.tabs button[aria-selected="true"] { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.finding { border-radius: var(--radius); padding: 0.8rem 1rem; margin: 0.6rem 0; border: 1px solid var(--line); background: var(--panel); }
.finding.error { background: var(--err-bg); border-color: var(--err-line); }
.finding.request { background: var(--warn-bg); border-color: var(--warn-line); }
.finding.ok { background: var(--ok-bg); border-color: var(--ok-line); }
.finding .tag { font-size: 0.78rem; font-weight: 800; text-transform: uppercase; letter-spacing: 0.04em; }

/* Guides */
article.guide { max-width: 44rem; }
article.guide table { border-collapse: collapse; width: 100%; overflow-x: auto; display: block; }
article.guide th, article.guide td { border: 1px solid var(--line); padding: 0.35rem 0.55rem; text-align: left; }

@media (max-width: 560px) {
  nav.site a { margin: 0 1rem 0 0; }
  header.site .wrap { padding-top: 0.5rem; padding-bottom: 0.5rem; }
}

/* Order review */
table.summary { border-collapse: collapse; width: 100%; margin-bottom: 0.8rem; }
table.summary th, table.summary td { text-align: left; vertical-align: top; padding: 0.45rem 0.6rem 0.45rem 0; border-bottom: 1px solid var(--line); }
table.summary th { color: var(--muted); font-weight: 600; width: 8rem; }
label.tick { display: flex; gap: 0.6rem; align-items: flex-start; font-weight: 500; margin: 0.8rem 0; }
label.tick input { width: auto; margin-top: 0.2rem; flex: none; }
.btn.disabled { opacity: 0.45; cursor: not-allowed; }